How to Convert a Lawn Mower Motor into an Outboard Engine

Converting a lawnmower motor into an outboard motor is a straightforward procedure. The conversion requires essential tools.

An outboard motor is a small gasoline engine with an exceptional propeller-producing motion.

Whether you’re a professional or a newbie, converting a lawnmower motor to a boat engine is an exciting experience. The task requires time, effort, motor interior experience, and boat motor knowledge.

The level of effort and experience involved determines the completion date.

The project can take two to four days, depending on your experience with motor interiors, assembling, and outboard knowledge.

Converting Lawn Mower Motor to a Boat Engine

Step 1: Unscrew the Lawnmower Casing

Before you embark on lawnmower motor to boat engine conversion, get acquainted with the basic technicalities involved physically and mechanically.

Remove grass clippings and debris, stick with the machine blades and rinse with water and soap.

For most people, converting a lawnmower motor to a boat motor is time-consuming, unnecessary, and could result in a product with sub-par quality and performance.

Screwdriver, cone rubber, rope, propeller, small rubber boat, metal cutter and bender, driveshaft, aluminum tube and pole, and power drill are essential items required for unscrewing and the technical aspects of the project.

The learning curve is within reach as taking the mower apart and reassembling the boat motor requires practical before commencing.

If you have a lawnmower sitting idle in your garage, perhaps you should consider converting it to a boat motor.

The motor conversion requires technical knowledge, and unscrewing the casing and engine is the first step. Follow the below steps to unbolt necessary screws on the machine:

Drain the oil:

Before you drain the oil of the machine, it is advisable to disconnect the spark plug wire. Drain the oil into a suitable container when it’s warm and wipe any spills.

Draining oil when it’s cold is not ideal as a little may get stuck.

Drain the gas:

Unscrewing the fuel hose clamp to drain the fuel should be your next step. Another method involves tracing the fuel hose route from the base of the gas tank to the engine.

Loosen the clamp, remove the hose and drain the fuel in a container.

Find the throttle linkage:

This component is under the machine’s carburetor. You will find a cable connecting and holding the throttle in position, unbolt the screw, remove the screw and set it aside.

Unscrew unnecessary bolts and nuts:

A lawnmower is a yard maintenance tool made with quality materials and offers exceptional qualities.

Ensure you unscrew unnecessary bolts and nuts, attaching any component to the machine seat and body parts.

Remove the drive belt:

The drive belt is in the crankshaft area of the machine under the engine. Pull the belt off gently and set it aside.

Unscrew the motor, remove the bolts and lift it out of the casing.

Step 2: Disassemble the Lawnmower and Mount the Propeller 

The machine’s motor, plugs, blades, and control system are essential components of your lawnmower. After unscrewing the mower’s casing and lifting the engine out, it’s time to unscrew significant components.

Remove the wire attached to the spark plug before unbolting it from the shaft engine’s vertical side and focus on the flywheel.

Unscrew the bolts holding the flywheel in position until the claws reach the bottom end of the crankshaft for easy removal.

Lawnmowers come in different shapes, designs, and blade in various sizes. You will find the blade attached to the motor. Use the screwdriver to unbolt it and set it aside.

The component delivering torque to the mower wheels for easy movement is your driveshaft. Unscrew the driveshaft and bring the aluminum tube closer.

Introduce the long driveshaft and weld the hollow aluminum tube to the top of the motor.

Please pick up the propeller and hold it against the drive shaft bottom before matching up the gears. It is advisable to ensure the turning propeller turns the drive shaft for efficient results.

Ensure the propeller is safe before bolting or welding the component to the aluminum pole, depending on your propeller type.

Make sure you weld the propeller properly and fit seamlessly for efficient operations.

Step 3: Create your Tiller

If you’re a fan of small boats or enjoy riding along the river on a beautiful morning, it’s time to live the life of your dreams.

Now that you can weld the propeller to the aluminum pole, turn the pole from the bottom up around 50 degrees.

It’s time to weld the aluminum tube’s bottom to the motor facing upwards.

You just created your tiller.

Step 4: Going All Out

After completing the above strategies, you’re one step away from testing your exceptional creation. Please pick up your aluminum pole, drill a hole, insert the rope and tie it.

Mount the motor on your boat’s setback, tie the rope, and enjoy the beautiful ride.

What Can you Make with an Old Lawnmower Engine?

Lawnmowers are exceptional tools, and the number of things you can do with the machine will impress you.

Recycling the engine and finding a new life for the machine is possible. Here are a few ideas you can make with an old lawnmower engine:

Convert into a Go-Kart

A Go-Kart is one of the easiest things to make with your old lawnmower engine because of its fun.

Creating the frame is a challenge for beginners and the most challenging part of the project.


You will not find lots of people performing this task because blenders are relatively cheap, but you can always lay claim to your creation.

The process requires a touch of creativity and thinking.

Boat Engine

If you enjoy boat sailing and have an old lawnmower engine in your garage, it’s time to explore. You can create a boat motor with your old mowing machine engine.

Most people attach a propeller to the machine for efficiency.

Ball launcher

Although the machine can be too powerful under certain conditions, another exciting project you can make with an old lawnmower engine is a ball launcher.

A ball launcher comes in handy for athletes involved in football, tennis, and baseball.


Over the years, lawnmower engines get thrown out or kept in the garage because owners saw no other use for the machine.​

If you are looking for a way to recycle your lawnmower’s engine or find a new life for the exceptional tool, consider converting the engine to a boat motor.

Lawnmowers engines are versatile, making it easy for users to convert into exciting things like boat motors, blenders, ball launchers, etc.

You can power a small conventional boat with your lawnmower engine outboard conversion with the above steps. It is advisable to add some extra fitting engine to prevent the engine from getting wet.